Over the past year, GitHub has transitioned its core Ruby on Rails application that powers github.com and api.github.com to Kubernetes clusters running on its metal cloud infrastructure, marking a significant milestone in its infrastructure evolution. This shift from a traditional setup using Unicorn processes and Puppet-managed servers to a containerized environment in Kubernetes was driven by the need for greater scalability, flexibility, and efficiency in deploying and managing services. The transition aimed to provide engineers with a self-service platform to experiment, deploy, and scale new services rapidly. The migration process involved extensive testing and validation, including creating a Kubernetes-powered deployment environment called "review lab" to facilitate exploratory testing and enhance deployment confidence. The transition to Kubernetes allowed GitHub to better handle growth and complexity while maintaining performance and reliability standards, even as they encountered challenges such as kernel panics during high load periods. Moving forward, GitHub is poised to extend Kubernetes deployment to more applications, including stateful workloads, thereby enabling the Site Reliability Engineering (SRE) team to focus more on delivering infrastructure products and improving the overall GitHub experience. The project was a collaborative effort involving multiple teams and drew significant inspiration and guidance from the Kubernetes open-source community.